Hitherto, as a method of forming metal oxide film on the surface of a metal substrate, an anodic oxidation method is well known (for example, see Japanese Laid-Open Patent Application Nos. 2001-68957 and 2001-152391). Now, in the anodic oxidation method, a predetermined voltage is applied to the metal substrate while the metal substrate is immersed in an acid bath in which an acid solution such as chromic acid, oxalic acid, sulfuric acid, or the like is fulfilled. For this reason, in the case of carrying out the anodic oxidation method, a power source and electrical wiring are required, and an operation thereof becomes complicated. In addition, power consumption becomes great, and this makes manufacturing costs thereof be increased. Further, there is a problem to tend to increase costs for the disposal of the acid solution.
Moreover, in the case where an oxide film with a plurality of patterns that are not connected to each other is formed by means of the anodic oxidation method, plural pieces of wiring for respectively applying a voltage to the plurality of patterns must be connected to a power source. Alternatively, after a series of pattern is formed and the anodic oxidation method is then carried out, the series of pattern must be divided to each of the plurality of patterns (patterning).
On the other hand, as a method of forming an oxide film on a silicon surface, various thermal oxidation methods such as a dry O2 oxidation method, a wet O2 oxidation method, and a steam oxidation method are mainly and widely utilized (for example, see Japanese Laid-Open Patent Application No. Hei. 5-226326).
However, since processing in each of these methods is carried out under high temperature of 600° C. or more, the energy consumption becomes great. Therefore, there is a problem that such a method cannot be applied to a substrate constituted from a material having a low melting point such as a resin substrate.